Question

Q. A five digit number is formed by writing the digits 1, 2, 3, 4, 5 in a random order without repetition. Then, find the probability that the number is divisible by 4.

Answer 1

Dear student

There are 4 combinations that make a number divisible by 4:

Last 2 digits being 12, 24, 32 and 52. When last 2 digits are 12, total such combination so are 6 that is 54312, 53412, 45312, 43512, 34512, 35412. Similarly 6 combinations for 24, 32 and 52 as last digits.

So totally 24 combinations

Total numbers possible :5!= 5*4*3*2*1 = 120

So talk possible = 24/120 = 1/5

Regards